Al Qaeda militants shot dead a man in southeastern Yemen on Thursday for allegedly giving the United States information used to carry out drone strikes against militants, witnesses and the SITE monitoring service said.

Al Qaeda militants shot dead a man in southeastern Yemen on Thursday for allegedly giving the United States information used to carry out drone strikes against militants, witnesses and the SITE monitoring service said.

Residents said the man was found shot dead on a sandy football pitch in the town of Shahr in Hadramout province.

Pictures posted on the Internet showed his body, dressed in Yemeni traditional clothes, hanging by its arms from a bar suspended from a football goalpost, on which a black al Qaeda flag also hung. A crowd of onlookers stood nearby.

The man was captured a year ago and accused of working for American intelligence and helping to guide drone strikes in 2012 and 2013, notably one on December 25, 2012, that killed five Islamist militants, SITE reported.

SITE said he had been killed by al Qaeda's Ansar al-Sharia group (Partisans of Islamic Law).

In a video titled "An American Spy in the Arabian Peninsula" posted on the Internet, a man identifying himself as Amin Abdullah Mohammed al-Mu'alimi confessed to assisting US intelligence.

The body of a man is seen tied to a soccer goal post after al Qaeda militants shot him to death accusing him of spying for the US outside al-Shihr city in Yemen. (Reuters photo)

He said he had been born in the Yemeni capital, Sanaa, but recruited in Sweden, and joined a security training course led by a Saudi intelligence officer.

He said American handlers had told him that some countries wanted to get rid of some people, and asked him to place tracking chips on three men named Ashraf, Majid and Mubarak.

Other black flags were found near Mu'alimi's body with slogans that read "An American Spy in the Arabian Peninsula" and "U.S. drone strikes kill Muslims", witnesses said.

Yemen, which shares a long border with top oil producer Saudi Arabia and receives military support from Washington, has been racked by lawlessness and violence since 2011, when mass protests forced veteran strongman Ali Abdullah Saleh to step down as president.

The US has stepped up drone strikes as part of a campaign against al Qaeda in the Arabian Peninsula (AQAP), regarded by Washington as the most active wing of the network.

Yemen, AQAP's main stronghold, is among a handful of countries where the US acknowledges using drones, although it does not comment on the practice.

Stabilising Yemen is an international priority amid fears of upheaval in a state that flanks major shipping lanes. The country is also struggling with demands by southern separatists for independence and an offensive by a Shi'ite Muslim Houthi movement to extend its control over the north.